Detroit DD15 GHG14 (2014-16) Fault Code: SPN 973 FMI 19 (CPC) Engine Retarder Selection Signal is Erratic

NOTE: Please see the step by step troubleshooting procedures for this specific code.

NOTE: If codes 168-0, 168-14, or 168-18 active fix those first.

NOTE: If ECM has been programmed recentely, check programming to ensure it is correct.

NOTE: This code is comnig from another computer on the vehicle (ABS, Transmission, etc…).